Rewterz penetration testing services help organizations determine if a cyber attacker can gain access to their critical assets while giving them detailed insights of the overall business impact of a cyber attack.
Before Rewterz got its start, the market was in dire need of a specialized and dedicated information security company. It was nearly impossible for businesses to find a trustworthy provider that could truly cover all of their bases. We wanted to meet this need, giving companies across the globe a chance to get ahead while knowing that their data is in good hands.
Rewterz penetration testing services help organizations determine if a cyber attacker can gain access to their critical assets while giving them detailed insights of the overall business impact of a cyber attack.
Before Rewterz got its start, the market was in dire need of a specialized and dedicated information security company. It was nearly impossible for businesses to find a trustworthy provider that could truly cover all of their bases. We wanted to meet this need, giving companies across the globe a chance to get ahead while knowing that their data is in good hands.
Medium
Besides typical RAT functions such as uploading, downloading and executing files, Reductor’s authors put a lot of effort into manipulating digital certificates and marking outbound TLS traffic with unique host-related identifiers. Reductor has been linked to Turla APT, based on the victimology. Reductor spreads by either infecting popular software distributions (Internet Downloader Manager, WinRAR, etc. and, for at least one victim, through a popular warez website over HTTP); or its decryptor/dropper is spread using COMpfun’s ability to download files on already infected hosts.
The malware adds digital certificates from its data section to the target host and allows the operators to add additional certificates remotely through a named pipe. The solution that Reductor’s developers found to mark TLS traffic is the most ingenious part. They don’t touch the network packets at all; instead developers analyzed the Firefox source code and Chrome binary code to patch the corresponding pseudo random number generation (PRNG) functions in the process’s memory.
In the first scenario, the attackers use infected software installers with 32- and 64-bit versions of Reductor included. These installers may be for popular Internet Download Manager, Office Activator, etc. In the second scenario, the targets are already infected with the COMpfun Trojan, which uses COM CLSID for persistence. After getting into the browser’s address space, the Trojan can receive the command to download additional modules from the C2. As a result, the target’s browser downloaded Reductor’s custom dropper-decryptor.
Reductor samples hold DER-encoded root X509v3 certificates in the .data section to add on the target hosts.
Data Manipulation
IP(s) / Hostname(s)
Malware Hash (MD5/SHA1/SH256)